Bit retention device

ABSTRACT

A bit retention device includes a shaft having a sidewall defining a hexagonal cavity extending from a first end thereof and a ball groove extending through the sidewall and communicating with the hexagonal cavity. A ball is disposed in the ball groove and a ball spring engages the ball and biases the ball toward the first end. An actuator sleeve surrounding the shaft includes an internal ramp engaging the ball. The internal ramp includes a shallow ramp portion having a first angle of inclination with respect to a center axis and a steep ramp portion having a second angle of inclination with respect to said center axis of said shaft that is greater than the first angle of inclination. A spring biased plunger assembly is disposed in the bore for biasing a bit received in the bore in a direction toward the insertion end.

FIELD

The present disclosure relates to power or hand tool bit retentiondevices, variously known as “auxiliary chucks,” “chucks,” “adapters,” or“bit holders” for removably receiving tool bits, such as fastenerdrivers, drill bits, or the like, for rotation therewith when the powertool is actuated or the hand tool is manually rotated. Moreparticularly, the present disclosure relates to a bit retention deviceconfigured for rapid and easy insertion and removal of a bit.

BACKGROUND AND SUMMARY

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Bit retention devices for power and hand tools have become increasinglycommon, especially as the need and desirability of wider versatility andthe use of power tools and hand tools has increased. Such bit retentiondevices allow the hand or power tool to be used with any of a number ofinterchangeable bits. This, in turn, has resulted in demands for greaterspeed, convenience, and ease for insertion and removal of tool bits fromthe bit retention device.

In one exemplary type of conventional bit retention device, one or moredetent balls are positioned within a hollow, barrel-shaped tool bitholder body and are resiliently biased into engagement with acircumferentially-extending groove or recess on the shank of the toolbit. Although this basic design has performed well, such conventionalquick-release bit retention devices frequently require the operator toactuate a sleeve, collar, or other component part during both theinsertion and the removal of the tool bit.

Accordingly, the present disclosure seeks to provide a bit retentiondevice that requires the operator to actuate its components only upontool bit removal. A “snap-in” type of bit retention device is providedfor a drill, driver, or other rotary hand or power tool. The bitretention device includes a shaft having a sidewall defining a hexagonalcavity extending from a first end thereof and a ball groove extendingthrough the sidewall and communicating with the hexagonal cavity. A ballis disposed in the ball groove and a ball spring engages the ball andbiases the ball toward the first end. An actuator sleeve surrounds theshaft and includes an internal ramp engaging the ball. The internal rampincludes a shallow ramp portion having a first angle of inclination withrespect to a center axis of the shaft and a steep portion having asecond angle of inclination with respect to the center axis of the shaftthat is greater than the first angle of inclination. The steep portionincludes a smaller diameter than the shallow ramp portion.

According to another aspect, the present disclosure provides a bitretention device, wherein a spring biased plunger biases the bit out ofengagement with the ball when the actuator sleeve is pulled forward.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a longitudinal cross-sectional view of a bit retention deviceaccording to the principles of the present disclosure;

FIG. 2 is an exploded perspective view of the bit retention device shownin FIG. 1;

FIG. 3 is an exploded perspective view of the plunger sub-assemblyaccording to the principles of the present disclosure;

FIG. 4 is an enlarged cross-sectional view of the bit retention deviceshown in FIG. 1 and illustrating the details of the ramp on the interiorsurface of the actuation sleeve, according to the principles of thepresent disclosure;

FIG. 5 is a cross-sectional view of the bit holder device shown with thesleeve pulled in a forward release position for allowing the removal ofthe tool bit;

FIG. 6 is a cross-sectional view of the bit holder device with a toolbit being inserted into the bit holder according to the principles ofthe present disclosure;

FIG. 7 is a cross-sectional view of the bit holder device with the toolbit being pressed into the bit retention device so that the ball is slidrearward along the ramp portion of the actuator sleeve;

FIG. 8 is a cross-sectional view of the bit retention device with thebit inserted further within the hexagonal cavity prior to the ball beingreceived in the ball groove of the screwdriver bit;

FIG. 9 illustrates a cross-sectional view of the bit retention devicehaving a “bit tip”-type bit being inserted therein according to theprinciples of the present disclosure;

FIG. 10 illustrates the “bit tip”-type being further inserted into thebit retention device with the ball being pushed rearward along the rampon the interior surface of the actuator sleeve;

FIG. 11 is a cross-sectional view showing the engagement of a “bittip”-type screwdriver bit fully inserted into the bit retention deviceaccording to the principles of the present disclosure;

FIG. 12 is a perspective view of a nose magnet applied to the bitretention device according to the principles of the present disclosure;

FIG. 13 is a cross-sectional view of the nose magnet applied to a bitretention device according to the principles of the present disclosure;

FIG. 14 is a perspective view of a non-marring nose cover applied to thebit retention device of the present disclosure;

FIG. 15 is a partial cross-sectional view of the non-marring nose coverapplied to a bit retention device according to the principles of thepresent disclosure; and

FIG. 16 is a cross-sectional view of a combined nose magnet and nosecover assembly according to the principles of the present disclosure.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on”, “engaged to”,“connected to” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto”, “directly connected to” or “directly coupled to” another element orlayer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.).

Spatially relative terms, such as “inner,” “outer,” “forward,”“rearward,” “lower,” “above,” “upper” and the like, may be used hereinfor ease of description to describe one element or feature'srelationship to another element(s) or feature(s) as illustrated in thefigures.

With reference to the accompanying Figures, the bit retention device 10according to the principles of the present disclosure will now bedescribed. The bit retention device 10 includes a shaft 12 defining apolygonal cavity 14 for receiving a tool bit or the like 16. Thepolygonal cavity 14 can be hexagonal. A plunger sub-assembly 18 isreceived in a bore 20 extending from the polygonal cavity 14. Anactuator sleeve 22 is disposed around a first end 24 of the shaft 12 andengages a ball 26 that is received in a ball groove 28 of the shaft 12.A ball spring 30 is disposed in the ball groove 28 and biases the ball26 against an interior ramp 32 of the actuator sleeve 22. A ball springretainer sleeve 34 surrounds the shaft 12 and retains a second end ofthe ball spring 30 within the ball groove 28.

An actuator spring 36 biases the actuator sleeve 22 in a rearwarddirection relative to the first end 24 of the shaft 12. A retainer clip40 is received in a recessed groove 42 in the first end 24 of the shaft12 and disposed against a forward end of the actuator spring 36. Asecond end of the actuator spring 36 is received against an interiorshoulder portion 44 of the actuator sleeve 22 in order to bias theactuator sleeve 22 in a rearward direction relative to the first end 24of the shaft 12. The actuator sleeve 22 includes a rear shoulder portion46 that can be located adjacent to the ramp 32 and can engage the ballspring retainer sleeve 34 at a forward end thereof to limit rearwardmovement of the actuator sleeve 22. The actuator sleeve 22 can include arearwardly extending cylindrical guide portion 48 that engages an outersurface of the ball spring retainer sleeve 34 for sliding engagementtherewith. The ball spring retainer sleeve 34 can include an internaldiameter portion 50 that snuggly receives the shaft 12 therein.

With reference to FIG. 3, the plunger assembly 18 can include a springseat 54 that is adapted to be press fit into a receiving groove 56within the bore 20 as illustrated in FIG. 1. The spring seat 54 includesa center post 58 which is adapted to receive a plunger spring 68thereon. A plunger member 66 is disposed against a forward end of theplunger spring 68.

The plunger member 66 has a recessed cavity 60 for receiving the plungerspring 68. The plunger sub-assembly 18 is inserted into the rear end ofthe bore 20 so that the forward end of the spring 68 engages the plungermember 66. The spring seat 54 is inserted into the bore 20 until thespring seat 54 engages the receiving groove 56 within the bore 20. Theplunger member 66 is designed to slide freely within the bore 20 whilethe spring 68 biases the plunger member 66 toward the first end 24 ofshaft 12.

With reference to FIG. 4, the ramp 32 of the actuator sleeve 22 will nowbe described. The ramp 32 includes a shallow ramp portion 32A and asteep ramp portion 32B. The shallow ramp portion 32A has a first angleof inclination α relative to the central axis X of the shaft 12 that canbe between 5 and 15 degrees, and more particularly about 10 degrees. Thesteep ramp portion 32B has a second angle of inclination β relative tothe central axis X that is larger than the angle of inclination α of theshallow ramp portion 32A. The steep ramp portion 32B can have an angleof inclination β relative to the central axis X that is between 13 and23 degrees, and more particularly about 18 degrees. The ramp portion 32can further include a third ramp portion 32C that is generally parallelto the axis X of the shaft 12 thereby defining a cylindrical wallportion thereon. The angles and positions of ramp portions 32A and 32Bare such that they allow the ball to pass the corner of the groove 70 ofthe power bit 16. In other words, the dimensions from the corner of thegroove to ramp surfaces 32A and 32B are greater than the ball diameterwhen the sleeve is seated in its rearward position. The spring 30 urgesthe ball 26 past the corner of the groove in the power bit to its fullyforward position. The ramp surface 32B and surface 32C direct the ballinto greater engagement with the groove 70 in the power bit 16.

During assembly, the plunger sub-assembly 18 is inserted into the bore20 until the spring seat 54 is disposed within the receiving groove 56within the bore 20. The ball spring retaining sleeve 34 is then slidover the shaft 12, and the ball spring 30 and ball 26 are inserted intothe ball groove 28 so that the ball spring retaining sleeve 34 overlapsthe rear end of the ball spring 30 in order to retain the ball spring 30within the ball groove 28. The actuator sleeve 22 is then inserted ontothe end of the shaft 12 and the actuator spring 36 is slid over the endof the shaft 12 inside of the actuator sleeve 22 so that the actuatorspring 36 abuts against the shoulder portion 44 of the actuator sleeve22. The retaining clip 40 is then installed on the shaft 12 so that theretainer clip 40 is received in the recessed groove 42 at the first end24 of the shaft 12.

It should be noted that the shaft 12 can be designed to be permanentlyinstalled on a rotating shaft of a power tool or can alternatively bedesigned to be removably engaged from a power tool or a hand tool. Thebit retention device 10 can be utilized for retaining various types ofhexagonal bits such as screwdriver bits and drill bits.

A common form of bit is referred to as a “power bit” which includes ahexagonal shank portion having an annular radiused groove 70 thereinthat is designed to receive a ball or other retaining member of aretention device. An exemplary “power bit”-type bit is illustrated inFIGS. 1, 2, and 5-8. When the bit retention device 10 of the presentdisclosure is utilized for retaining a power bit, the ball 26 isreceived in the annular groove 70 of the bit 16 as illustrated inFIG. 1. In this position, the ramp portion 32C retains the ball withinthe annular groove 70 of the bit 16. In order to release the bit 16 fromthe retention device 10, the actuator sleeve 22 is pulled in a forwarddirection as illustrated in FIG. 5 so that the ball 26 is able to moveradially outward out of the annular groove 70 and the plunger assembly18 pushes the bit forward so that the ball groove 70 is no longer inalignment with the ball 26. The sleeve 22 can then be released and thebit 16 can be extracted with the same hand, thus making it a simple onehand operation to remove the bit 16.

In order to insert a bit into the bit retention device, the bit isinserted into the polygonal cavity 14, as illustrated in FIG. 6, untilthe end of the bit 16 engages the ball 26, as shown in FIG. 6. The bit16 is then pressed further inward so that the ball 26 presses againstthe spring 30 and moves rearward in the ball groove 28 and upward alongthe ramp 32 of the actuator sleeve 22. Once the ball 26 moves far enoughalong the ramp 32, the ball 26 rides along a vertex of the hexagonalsurface of the bit 16. The bit 16 then presses against the plunger 66and presses the plunger 66 rearward as illustrated in FIG. 8. The bit 16is then pressed further inwards to its fully locked position asillustrated in FIG. 1.

Another type of bit is often referred to as a “bit tip” as illustratedby references numeral 80 in FIGS. 9-11. For installation of a bit tip 80in the bit retention device 10, the bit tip 80 is inserted into thepolygonal cavity 14 as illustrated in FIG. 9. As the bit tip 80 engagesthe ball 26, the ball is pressed rearward, compressing the ball spring30 and the ball is caused to move relative to the ramp 32 so that theball 26 can move radially outward as it traverses the ramp 32, asillustrated in FIG. 10. As the ball 26 moves radially outward to asufficient extent, the bit tip 80 is then able to move freely inwardagainst the biasing force of the plunger assembly 18. The bit tip 80 isthen pressed inward to its full extent as illustrated in FIG. 11.

In the fully inserted position, the ball 26 is biased against theshallow ramp portion 32A of the ramp 32 of the actuator sleeve 22. Thesmaller angle of inclination α of the shallow ramp portion 32A providesa radial force against the ball 26 that is sufficient for retaining thebit tip 80 within the bit retention device 10 without the ball 26 havingto engage any recess on the bit tip 80.

In order to release the bit tip 80 from the bit retention device 10, theactuator sleeve 22 is pulled in a forward direction and the plunger 18biases the bit tip forward a sufficient amount for the bit tip 80 to beremoved by the user. The use of a ramp 32 having a shallow ramp portion32A and a steep ramp portion 32B allows the bit retention device 10 tobe utilized with various kinds of tool bits wherein the ball 26 is ableto be received in an annular groove of a “power bit”-type bit with rampportion 32B causing the ball 26 to move radially inward to a greaterextent than the shallow ramp portion 32A so that the ball is properlyreceived within the ball groove 70 of the power bit. The greater angleof inclination of the steep ramp portion 32B allows the ramp 32 to beshorter and therefore the actuator sleeve 22 can be more compact. Theshallow ramp portion 32A provides a sufficient radial inward force toretain a “bit tip”-type bit within the bit retention device 10 withoutthe ball 26 needing to engage a recess on the bit.

The spring biased ball 26 allows a user to insert a bit 16 into the bitretention device 10 without having to use a second hand tosimultaneously engage the actuator sleeve 22. Instead, the user can holdthe tool with one hand and insert the bit 16, 80 into the bit retentiondevice with the other hand. In order to release the bit 16, 80 from thebit retention device 10, the actuator sleeve 22 can then be pulledforward and the plunger assembly 18 presses the bit 16, 80 forward asufficient amount so that the sleeve 22 can be released and the bit 16,80 can be grasped by the same hand and removed from the bit retentiondevice 10, thus making it a one-hand operation to remove the bit 16. Theplunger spring 68 can be provided with a sufficient spring force tocause the bit 16, 80 to be moved forward upon activation of the actuatorsleeve 22, but not too strong to eject the bit 16, 80 from the bitretention device.

As shown in FIGS. 12-13, a nose magnet 90 can have an annular shape witha central aperture 92 magnet 90 has concentric ribs 94 that conform tothe front of the shaft 12 and sleeve 22 to locate the magnet 90 and holdit concentric to the bit retention device 10. The magnet holds to theshaft in sleeve and holds a fastener in engagement with the bit 16because the nose magnet 90 is external to the bit retention device 10,it does not attract metal debris inside the bit retaining device 10.Furthermore, the magnet 90 can be adhered to the actuator sleeve orotherwise connected thereto so that the magnet does not become dislodgedfrom the bit retention device 10. Alternatively, the nose magnet 90 canbe removably attached under its magnetic traction to the actuator sleeve22 so that it can be easily removed and reinserted by the user, asdesired.

With reference to FIGS. 14-15, a non-marring nose cover 100 can bedisposed over the bit retention device 10. The non-marring nose cover100 can be made of a plastic or elastomeric material and can be formedsuch that it can be slipped over the actuator sleeve 22 and retainsitself in place with a slight interference or wrap around portion 102that wraps around the proximal end of the actuator sleeve 22. The nosecover 100 can further include a distal end portion that wraps over theend portion of the bit retention device 10 with a central aperture 106for receiving a bit 16 therein. The non-marring nose cover 100 preventsthe knurled metal sleeve 22 from marring a work material. The forwardportion 104 reduces or eliminates infiltration of dust and debris intothe bit retention device allowing it to operate more smoothly for alonger period of time. The aperture 106 in the forward portion 104 canfit snugly around the bit 16.

As shown in FIG. 16, the bit retention device 10 can further be providedwith an over-molded magnetic nose cover 110. The over-molded magneticnose cover 110 can include a nose magnet 90 constructed generally asdescribed above. A plastic cover 112 can be over-molded on the nosemagnet 90 or alternatively, the nose magnet 90 can be inserted into thecover 112. The cover 112 can be made of plastic or elastomer and isdesigned to prevent the knurled metal sleeve 22 from marring the workmaterial. A slight interference between the cover 112 and the sleeve 22may retain the cover onto the shaft or, alternatively, a wrap aroundportion or adhesives can be utilized for securing the cover 112 onto theactuator sleeve 22. In assembled condition as illustrated in FIG. 16,the nose magnet 90 will attract a fastener to the bit 16 hold thefastener in place. Furthermore, the cover portion 112 protects the workpiece from being marred while a fastener is being inserted. It should benoted that the magnet 90 may also retain the cover onto the shaft toprovide a cover 112 and magnet 90 that can be easily removed as desiredby the user.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

What is claimed is:
 1. A bit retention device, comprising: a shafthaving a sidewall defining a bit receiving cavity extending from a firstend thereof and a ball groove extending through said sidewall andcommunicating with said bit receiving cavity; a ball disposed in saidball groove; a ball spring engaging said ball and biasing said balltoward said first end; an actuator sleeve surrounding said shaft andincluding an internal ramp engaging said ball, said internal rampincluding a first shallow ramp portion having a first angle ofinclination with respect to a center axis of said shaft, a second steepramp portion having a second angle of inclination with respect to saidcenter axis of said shaft that is greater than said first angle ofinclination, said second steep ramp portion having a smaller diameterthan said first shallow ramp portion and a third generally cylindricalportion disposed adjacent to said second steep ramp portion with saidsecond steep ramp portion disposed between said first shallow rampportion and said third generally cylindrical portion, wherein each ofsaid first shallow ramp portion, said second steep ramp portion and saidthird generally cylindrical portion are adapted to engage an outersurface of the ball.
 2. The bit retention device according to claim 1,further comprising an actuator spring biasing said actuator sleeve awayfrom said first end of said shaft.
 3. The bit retention device accordingto claim 1, wherein said ball groove extends in an axial direction and aspring retainer sleeve surrounds a rearward portion of said ball grooveand retains said ball spring in said ball groove.
 4. The bit retentiondevice according to claim 3, wherein said actuator sleeve is slidablymounted on an exterior surface of said spring retainer sleeve.
 5. Thebit retention device according to claim 4, wherein said actuator sleeveincludes an interior shoulder that abuts against said spring retainersleeve when said actuator sleeve is in a rearward-most position.
 6. Thebit retention device according to claim 1, wherein said bit receivingcavity has a polygonal cross-section.
 7. The bit retention deviceaccording to claim 1, wherein said bit retention device is operable toretain a first bit having an annular groove in a surface thereof withsaid ball being pushed into the annular ball groove by said steep rampportion and said bit retention device is operable to retain a second bitwithout an annular ball groove with said ball being disposed betweensaid shallow ramp portion and a surface of said second bit.
 8. The bitretention device according to claim 7, wherein when said first bithaving an annular groove in a surface thereof is inserted into said bitretention device, a distance between said internal ramp and a rearwardedge of said annular groove is greater than a diameter of said ball. 9.The bit retention device according to claim 1, wherein said first angleof inclination of said shallow ramp portion is between 5 and 15 degrees.10. The bit retention device according to claim 9, wherein said secondangle of inclination of said steep ramp portion is between 13 and 23degrees.
 11. The bit retention device according to claim 1, furthercomprising an elastomeric cover disposed over a forward end of saidactuator sleeve.
 12. The bit retention device according to claim 1,further comprising a nose magnet attached to a forward end of saidactuator sleeve.
 13. The bit retention device according to claim 12,further comprising an elastomeric cover disposed over said nose magnet.14. A bit retention device, comprising: a shaft having a sidewalldefining a polygonal cavity extending from a first end thereof, a ballgroove extending through said sidewall and communicating with saidpolygonal cavity and a bore extending axially from said polygonalcavity; a ball disposed in said ball groove; a ball spring disposed insaid ball groove and engaging said ball and biasing said ball towardsaid first end; an actuator sleeve surrounding said shaft and includingan internal ramp engaging said ball; and a spring biased plungerassembly disposed in said bore for biasing a bit received in said borein a direction toward said first end, wherein said actuator sleeve isfree from any device holding said actuator sleeve in an open positionsuch that a bit can be inserted into said bit retention device withoutany need for the actuator sleeve being held in said open position,wherein said ball groove extends in an axial direction and a springretainer sleeve directly surrounds said shaft and only a rearwardportion of said ball groove and only a rearward portion of said ballspring to retain said ball spring in said ball groove.
 15. The bitretention device according to claim 14, wherein said bit retentiondevice includes only one spring loaded ball.
 16. The bit retentiondevice according to claim 14, further comprising an actuator springbiasing said actuator sleeve away from said first end of said shaft.